The present disclosure describes systems and techniques relating to an integer non-uniform constellation (NUC) for high-order quadrature amplitude modulation (QAM), such as 1024-QAM for use in communication systems.
Quadrature amplitude modulation (QAM) is a modulation scheme that maps bits into constellation points (also referred to as grid points or QAM symbols), according to a mapping rule. Each constellation point (e.g., carrying phase and magnitude information) corresponds to a binary bit pattern (e.g., corresponding to an array of bits). For example, an M-QAM mapping rule can be used to map M number of constellation points to M number of bit patterns, wherein each bit pattern includes L=log2(M) number of bits. Common forms of QAM include 16-QAM, 64-QAM, and 256-QAM.
In some implementations, the M number of constellation points can be represented in a constellation diagram that includes a real axis and an imaginary axis. Each constellation point can thus be represented by its respective real coordinate (also referred to as an in-phase (I) component) and imaginary coordinate (also referred to as a quadrature (Q) component). For example, an M-QAM symbol, X, can be represented by its coordinates (Re(X), Im(X)), which is mapped to a particular bit pattern L represented by the series of bits (C0-CL-1), according to a specified M-QAM mapping rule.